Method of making alpha rubber article



2 1 927 o. KRICHBAUM METHOD OF, MAKING A RUB 5BR ARTICLE Original; Filed Feb. 9 5

. I10 (-2 YLZFO I? Patented Apr. 26, 1927.

UNITED STATES PATENT OFFICE.

ORA KBICHBAUM, DELAWARE, QHIO.

METHOD or MAKING A RUBBER narrow.

Driginal application filed February 27, 1925, Serial No. 12,044. Divided and this application filed July 6, 1926. Serial No. 120,624.

The present invention relates to a rubber article adapted for inflation, or to .contain water or other fluid.

This case is a division of my co-pending application, No. 12,044; filed February 27, 1925. a

One object of the invention is to provide a structure in which the bulging of one part of the article is prevented when pressure is applied to another part thereof.

Another object is to provide a structure which unites the inner walls of the article, thereby to resist local bulging effects when the article is inflated. A furtherobject is to provide a method of making the article.

Reference should be had to the accompanying drawings in which Fig. 1 is a top plan view, with a portion in section;

Fig. 2 is a sectional view Fig. 3 is a plan view of a member used in,

making the article; and

Fi 4 is a sectional elevation of a form on w ich the article is molded.

The article which will be described is a rubber air cushion, as this is the embodiment of the invention so far. developed, but no limitation of the invention is intended by the specific description.

The cushion is formed in any desired shape, but the one herein shown is rectangu lar or substantially so and consists of two outside members A and-B which are formed of sheet rubber. These outside members are secured to ether at or adjacent their ed es, so that t e article forms a closed enve ope or bag.

The manner of securi ber may be by a suita le rubber cement which is well known in the rubber art, but I prefer to secure attachment by vulcanizing the rubber sheets together, at their contacting edge portions.

Inside the envelope formed by the members A and B is an intermediate flexible member C which is preferably formed of rubber. This intermediate member C is se cured to the inside surfaces of the members A and B at a plurality of small areas or spots and preferablythe spots of attachmentbetween the intermediate member C and the "member A are staggered with respect to the spots of attachment between the members C and B. Preferably the edges of the intermediate member 0 are free and unse- "as that of the inside of the envelo the sheets of rub members of the article.

cured to either the members A or, B so that air may pass around the edges.

From the description given it will be seen that the structure provides in effect a plurality of air pockets, on both sides of the intermediate member C, but these pockets are connected with contiguous pockets, so that air may pass between pockets but there is a restricted passage of air and because of this the air cannot rush to one part of the envelope when pressure is applied to another portion of the envelope.

In another aspect of the invention the intermediate member C may be viewed as forming a flexible connection between the outer members A and B whereby these members are-prevented from unduly bulging under air pressure.

For the purpose of inflating the article a suitable valve is provided. This is indi-- cated at G in Fig. 1. Such valves are well known in the art and need no description.

I will now describe the method by which I prefer to make the article described.

Two sheets of raw rubber of the proper size and an intermediate sheet of raw rubber of proper size, are taken. A sheet of paper or equivalent material for the purpose is provided, which in size is the same which is sli htly larger than the intermedlate sheet C. uch a sheet is shown atD in Fig. 3: This sheet is provided with a pluralit of openings E which are spaced apart an arranged as desired. V

This sheet D is laid upon one of the sheets of rubber which will form one of the outer Then the intermediate sheet of raw rubber is laid upon the'sheet D. Then a second sheet of paper or equivalent material in all respects similar to the sheet D is laid over the intermediate sheet of raw rubber and then the second outside sheet of raw rubber is laid over the second sheet D.

Thus it will be seen that the outside rubber sheets are in contact at or adjacent their edges, and further that these outside raw rubber sheets are in contact with the intermediate sheet of raw rubber at spots where there are holes through the paper sheets D.

Preferabl the openings E in the two sheets D w ich are used as described are staggered with respect to each other, so that contact spots between the intermediate rubher sheet and one of the outside rubber sheets are staggered with respect to e contact spots between the intermediate rubber sheet and the other outside rubber sheet.

When the rubber sheets and paper sheets are arranged as described, the article is vulcanized and there will be areas of attachment between the. outside rubber sheets at their edges and also between the intermediate rubber sheet and the outside rubber sheets at places where there were holes in the paper sheets.

I prefer to vulcanize the article upon a round mandrel such as indicated at F, in Fig. 4, so that the finished article will have a tendency to roll up easily, into a' scroll form, in which form it is easy to carry or store it. 5

Having thus described my invention, I claim:

1. The method of manufacturing a rubber article which consists of taking two sheets of raw rubber of desired size and a sheet of raw rubber of smaller size, lacing separating sheets of suitable material formed with ho es therein upon opposite sides of the sheet of raw rubber of smaller size, then placing the said sheet of rubber with the separating material assembled with respect thereto between the two sheets of rubber and vulcanizing the assembled sheets.

2. The method of manufacturin a. rubber article which consists in takmg two sheets of raw rubber of the desired size and a sheet of raw rubber of smaller size, placin sheets of paper'or equivalent material wi holes in it upon opposite sides of the sheet 4 of raw rubber of smaller size which sheets of paper are slightly smaller than the lar e sheets of rubber, placing said sheets of ru her and paper between the other larger sheets of rubber and vulcanizing .the assembled sheets.

3. The method of manufacturing a rubber article, which consists of taking two sheets of raw rubber of desired size and a sheet of raw rubber of smaller size, placing separating sheets of suitable material formed with holes therein upon opposite sides of the sheet of rubber of smaller size, then placing said sheet of rubber, with its separating material assembled with respect thereto, between the two larger sheets of rubber, then wrapping the combined sheets of rubber around a cylindrical mandrel and vulcanizing the assembled sheets.

4'. The method of manufacturing a rubber article, which consists of taking two sheets of raw rubber of the desired size and a sheet of raw rubber of smaller size, placin sheets of paper or equivalent materials wit holes in-it on opposite sides of the sheet of raw rubber of smaller size, which sheets of paper are slightly smaller than the lar er sheet of rubber, placin saidsheets of ru ber and paper between t e other larger sheets of rubber, wrapping said sheets around a c lindrical 'mandrel" and vulcanizing t e assembledsheets.

In testimony whereof, I hereunto afiix my signature.

- ORA KRIOHBAUM. 

